1. Field of the Invention
The present invention relates to an optical medium which can visualize an optical image using a Fourier transform lens, and to a method of observing the image using the Fourier transform lens having the optical image formed thereon.
2. Background Art
In the past, various premium products and post cards have been utilized as advertising media, and become recently important items used as tools, in particular, for promotion of new products and events.
Such tools tend to become less popular. Therefore, there is a need for something that has a new design and unpredictability and contributes to promotion activity.
For example, a post card with a photographic image, in which a lenticular lens is incorporated, has been proposed (e.g., see Patent Document 1).
However, in the case of such a post card with a photographic image, in which a lenticular lens is incorporated, a plurality of photographs to be projected must be prepared, and lenses corresponding to the number of photographs must be formed. This is problematic in taking a large cost.
As recently known advertising media, various products have been developed and proposed.
For example, advertisement of a product is carried out by providing a column for advertisement in a newspaper or magazine, and forming an expression of a printed image in the column, comprising characters, figures, patterns and the like, having a relation to a presentation of the product to be advertised, including a trade name, a trademark, a manufacturer, an explanation or the like.
Alternatively, advertisement is practiced by preparing leaflets or catalogs concerning a product, and distributing them to an unspecified large number of people to make the product printed thereon be widely known and attract public interest.
Moreover, in some cases, a product is advertised utilizing, for example, neon signs in a street, chiefly depending on the sense of sight, but in other cases, a product is advertised utilizing radios or broadcasting on the street or the like, mainly depending on a voice. Otherwise, such advertisement is sometimes carried out using televisions, chiefly depending on a voice and an image.
However, the advertisement depending on such advertising media is for advertising a product to an unspecified large number of people. Usually, each of them is not so much interested in the advertised product, even if he or she views or listens to it.
Recently, people have had tendency to exhibit strong dislike against noise and loudness caused by advertisement and thus be bored therewith. Accordingly, they probably avoid viewing or listening to advertisement of a product in which they are not so interested, and they would throw away leaflets or catalogs for the advertisement without taking a look. Therefore, such people do not pay any attention to advertisement of a product, and the effect of such advertisement cannot be expected.
Also, optical media by which optical images can be observed have been used as promotion media or toys for use in advertisement or promotions of new products.
Such an optical medium utilizes, for example, a Fourier transform lens, and is constructed so that it can visually show various optical images formed in advance thereon using light irradiation or the like and the user can observe and enjoy the images (e.g., see Patent Document 2).
In an optical media utilizing a conventional Fourier transform lens, when observing an optical image formed on the Fourier transform lens with eyes, the Fourier transform lens must be irradiated with light emitted from a point light source on the side opposite to the side on which the user is observing the image with his eyes.
As such a point light source, for example, the sun, a candle, a spot light, fireworks or the like can be used. However, if viewing the Fourier transform lens while holding the lens toward the sun, there is a significant risk of damaging the eyes due to too strong light.
Especially, in a case where a medium using such a Fourier transform lens is utilized for distribution to children, a measure must be taken to prevent accidents, such as by printing on the medium a note for instructing or warning the children not to observe the Fourier transform lens while directing it toward the sun.
However, it is probable that the children will not become aware of the note or cannot read it, or otherwise it is possible that they will use the Fourier transform lens aimlessly or unintentionally directing it toward the sun. Thus, a risk that a user takes an inappropriate use of the lens still remains.
To attract interest of consumers, it is effective to use a new optical medium utilizing a Fourier transform lens as a means for promotion. However, a process for laminating a sheet having a Fourier transform lens formed thereon onto a sheet having information for advertisement printed thereon must be carried out, thereby requiring significant time, labor and cost. Accordingly, it is currently difficult to readily use a medium utilizing a Fourier transform lens as a means for advertisement.
Documents Cited:
Patent Document 1: TOKUKAI No. 2001-166402, KOHO
Patent Document 2: TOKUKAI No. 2004-7758, KOHO